40 minutes from Bilbao sits a 10th century hermitage on an island that is only reachable by foot.
The hike to the hermitage is just as gorgeous as the actual island, with steep cliffs and breathtaking views of the Cantabrian Sea.
Half way to the island, there's a small bar with amazing pintxos (Basque tapas), and tables where you can enjoy a drink and look out over the sea.
There are over 200 steps that connect the mainland to the island, and once on the island, you can explore the church (though it rarely open) and small shelter, which is ideal for a picnic.
It's a great daytrip from Bilbao for experienced and novice hikers alike.